Photocatalytic hydrogen production with CuS/ZnO from aqueous Na2S + Na2SO3 solution

The photocatalytic hydrogen production in the sacrificial S2--SO32- anions was investigated with ZnO in the addition of metal sulfides containing Ag2S, CuS, Fe2S3, and NiS. In the absence of metal sulfides, the photocatalytic H-2 evolution using ZnO was observed with 255 mu mol g(-1). The CuS amount and the concentrations of S2- and SO32- ions were optimized. It was found that ternary component semiconductor CuS/ZnS/ZnO was formed during the photocatalytic hydrogen production in the aqueous Na2S + Na2SO3 solution. The photocatalytic hydrogen evolution with CuS/ZnS/ZnO in the 0.4 M Na2S-0.4 M Na2SO3 solution was more than about 8.5 times better compared with those obtained with only ZnO. The CuS clusters on the surface of ZnS/ZnO seem to play an important role on the separation for electron-hole pair and the enhancement of H-2 production. Nano-sized ZnS/ZnO photocatalytic hydrogen technology has great potential for low-cost, environmentally friendly solar-hydrogen production to support the future hydrogen economy. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.